Anytime between the signing of the Anglo japanese alliance and world war 1 . Had the us and an other power declared war on Japan for whatever reason would britian honor their alliance or abandon their ally for better relations with the U.S.
I answered no.
But to declare war on the Japan that defeated Russia, the USA is first going to need a strong investment in its navy.
How much would having the British & the commonwealth neutral in a Pacific war help the Japanese?
Would an Anglo-American war mean an invasion of Canada? How would that go down?
If the USA for whatever reason launched an unprovoked attack against Japan (hello Skippy), the British would probably launch a trade embargo against the USA, as well as offer mediation..
At that time, I don't think Britain would risk losing Canada--that is just so much more valuable than anything that the British might take from the USA. And if the USA was determined, Canada would most likely fall. (Any war that had Britain seriously committed elsewhere would likely see France or Germany fishing in troubled waters...)
I can see one way that Japan could attempt to neutralize the USN in one fell swoop...go after the Great White Fleet in a surprise attack as it was visiting Japan. That would, however, really poss off everyone, and I think Britain would be smart enough to stay away from the mayhem...
It depends on the circumstances, but I think it's far more likely that Britain would offer to mediate a pre-WWI conflict between the US and Japan.
Agreed. Mediation. Unless it's a Pearl Harbor, in which case the Empire drops Japan like a hot rock and someone else offers mediation. France? Germany?
If it's a surprise attack, would anyone offer mediation? And would the USA be interested in anything at all livable for Japan? There's no chance, at this time, of invading Japan, but, I feel confident that, with motivation, the US could develop a fleet train capable of long range operations.